It is proposed to use the extended boundary conditions method and effective medium theories to study the distribution of Radio Frequency fields inside the human bodies as it is subjected to MRI irradiation. This method has proved successful in the study of scattering of electromagnetic fields in a large number of applications. For example, in radar detection and in optical properties of colloidal aggregates. Although this method is ideally suited to study the MRI problems, has never been used in this area. We will consider materials that resemble human organs. On one hand we will consider compartmentalized objects, to mimic conglomerate of various organs with their boundaries. It has been said that heating occurs preferably at the interfaces. We will check that. On the other hand we will consider granular materials, to mimic non-homogeneous organs like lungs and kidney. In all those cases we will pay particular attention to the specific absorption rate inside the tissue.